I'm a newby too... I have a S5 IS and I would like to use F16 and more shuter time, however it still with the original F8 and 15''
What's wrong? :-/
CHDK doesn't alter Canon's menus or Canon's on-screen display. To get past Canon's limitations, go to CHDK menu -> extra photo operations -> shutter speed override / aperture override or use a suitable script.